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Palladium-Catalyzed Allylic Substitution Reactions (Palladium-Catalyze + allylic_substitution_reaction)

Distribution by Scientific Domains
Chemistry100%

Selected Abstracts

Pyranoside Phosphite-Oxazoline Ligand Library: Highly Efficient Modular P,N Ligands for Palladium-Catalyzed Allylic Substitution Reactions.

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 18 2009
A Study of the Key Palladium Allyl Intermediates
Abstract We have screened a library of modular phosphite-oxazoline ligands for asymmetric allylic substitution reactions. The library is efficiently prepared from the commercially available and cheap D -glucosamine. The introduction of a phosphite moiety into the ligand design is highly advantageous for the product outcome. Therefore, this ligand library affords good-to-excellent reaction rates [TOFs up to 600 mol substrate×(mol Pd×h),1] and enantioselectivities (ees up to 99%) and, at the same time, shows a broad scope for mono-, di- and trisubstituted linear hindered and unhindered substrates and cyclic substrates. The NMR studies on the palladium allyl intermediates provide a deeper understanding about the effect of the ligand parameters on the origin of enantioselectivity. [source]

Modular Furanoside Phosphite-Phosphoroamidites, a Readily Available Ligand Library for Asymmetric Palladium-Catalyzed Allylic Substitution Reactions.

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 10 2009
Origin of Enantioselectivity
Abstract A library of furanoside phosphite-phosphoroamidite ligands has been synthesized and screened in the palladium-catalyzed allylic substitution reactions of several substrate types. These series of ligands can be prepared efficiently from easily accessible D -xylose and D -glucose. Their modular nature enables the position of the phosphoroamidite group, configuration of C-3 of the furanoside backbone and the substituents/configurations in the biaryl phosphite/phosphoroamidite moieties to be easily and systematically varied. By carefully selecting the ligand components, therefore, high regio- and enantioselectivities (ees up to 98%) and good activities have been achieved in a broad range of mono- and disubstituted hindered and unhindered linear and cyclic substrates. The NMR studies on the palladium-,-allyl intermediates provide a deeper understanding about the effect of the ligand parameters on the origin of enantioselectivity. They also indicate that the nucleophilic attack takes place predominantly at the allylic terminal carbon atom located trans to the phosphoroamidite moiety. [source]

New Carbohydrate-Based Phosphite-Oxazoline Ligands as Highly Versatile Ligands for Palladium-Catalyzed Allylic Substitution Reactions

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 15 2005
Yvette Mata
Abstract We have designed and synthesized a new family of readily available phosphite-oxazoline ligands for Pd-catalyzed asymmetric allylic substitution reactions. These ligands can be tuned in two regions to explore their effect on catalytic performance. By carefully selecting the ligand components, we obtained high enantioselectivities in the Pd-catalyzed allylic substitution in substrates with different steric properties [source]

Fischer Chromium Carbene Complexes as Nucleophiles in Palladium-Catalyzed Allylic Substitution Reactions.

CHEMINFORM, Issue 4 2003
Dusan Drahonovsky
Abstract For Abstract see ChemInform Abstract in Full Text. [source]

ChemInform Abstract: Novel Ferrocene Modified P,N-Ligands for Enantioselective Palladium-Catalyzed Allylic Substitution Reactions.

CHEMINFORM, Issue 18 2002
Shu-Li You
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

ChemInform Abstract: Enantioconvergent Synthesis by Sequential Asymmetric Horner,Wadsworth,Emmons and Palladium-Catalyzed Allylic Substitution Reactions.

CHEMINFORM, Issue 8 2002
Torben M. Pedersen
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]